Intelligent phones are popularly employed nowadays, in which personal users may stall, configure and run application program randomly. Further, terminal equipments, like personal computer, may operate intelligent phones. In prior art, GSM protocol 3GPP27.010 defines a multiplex (MUX) protocol for interaction between terminal equipments and user equipments. The MUX protocol provides a virtual connection including multiple channels for communicating terminal devices and user equipments, and each channel may function as an actual channel for one service. An intelligent phone comprises an application processor (AP) and a modem, between which a physical link is provided and corresponds to multiple virtual channels according to GSM protocol 3GPP27.010.
In a prior art intelligent phone, an application processor normally controls a modem simply in the case of single-card single-standby application. Taking an intelligent phone with an application processor and a modem as an example, FIG. 1 schematically illustrates a MUX operation of the application processor and the modem in prior art. Referring to FIG. 1, a physical link is established between the terminal equipment (TE) and the user equipment (UE) through serial interface. Hereinafter, the terminal equipment has an extendable definition referring to, for instance, an application processor embedded into the intelligent phone, and/or application processor embedded into a personal computer. Similarly, the user equipment has an extendable definition referring to, for instance, the modem in the intelligent phone. As for a single-card single-standby intelligent phone, when an intelligent phone is dialing for calling, one channel is specified as a link between the AP and the modem for point-to-point protocol (PPP) data dialing, and another channel is specified for AT command. As for the modem of the single-card single-standby intelligent phone, any MUX channel, upon receiving a prompt of calling (e.g. a prompt “RING” of standard AT command), can exclusively identify a corresponding User Identification Module card (e.g. SIM card), i.e. the only SIM card in the modem card slot. In this case, this session could be processed in any channel supporting AT command by ways of connection or refusal etc. The dialing data of the intelligent phone are processed by the application processor, A/D converted by modem, and transferred to the only SIM card in the modem card slot.
The prior art multi-card multi-standby intelligent phones are increasingly popular, incurring more complicated situations upon receiving dialing service request or other service request, for example it could not be found to which SIM card the service request, e.g. dialing, should be sent, to which SIM card a calling prompt on a channel is directed, in which MUX channel the calling is processed, and the like. In general, a MUX channel is unable to be combined to a card when there are multiple cards, resulting in unpredictable mess in use with multiple cards.
Many existing patents, for example US patent publication Number US2008/0167074A1, are relevant to multi-card multi-standby phones, but do not propose a solution to overcome the drawback of prior art.